Using the Command-Line Interface

• User EXEC mode

• Privileged EXEC mode

• VLAN database mode

• Global configuration mode

• Interface configuration mode

• Line configuration mode

The supported commands can vary depending on the version of IOS software in use. To view a comprehensive list of commands, enter a question mark (?) at the prompt.

Switch> ? 
 
ATM> ? 

Switch# configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z. 
 
ATM# configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
 

The supported commands can vary depending on the version of IOS software in use. To view a comprehensive list of commands, enter a question mark (?) at the prompt.

Switch(config)# ? 
Switch(config)# 

ATM(config)# ? 
ATM(config)# 

To exit global configuration command mode and return to privileged EXEC mode, enter the end or exit command, or press Ctrl-Z.

Use the interface type_number.subif command to access interface configuration mode. The new prompt indicates interface configuration mode.

Switch(config-if)#

ATM(config-if)# 

In one of the following examples, ATM interface 1 is about to be configured.

The following examples show you how to access interface configuration mode by using the int command:

Switch(config-subif)# int FastEthernet 0/1
 
ATM(config-subif)# int atm1.1 multipoint
 

The supported commands can vary depending on the version of IOS software in use. To view a comprehensive list of commands, enter a question mark (?) at the prompt.

Switch(config-subif)# ? 
Switch(config-if)# 
 
ATM(config-subif)# ? 
ATM(config-if)# 
 

To exit interface configuration mode and return to global configuration mode, enter the exit command. To exit interface configuration mode and return to privileged EXEC mode, enter the end command, or press Ctrl-Z.

Use the line vty line_number [ending_line_number] command to enter line configuration mode. The new prompt indicates line configuration mode. The following examples shows how to enter line configuration mode for virtual terminal line 7:

Switch(config)# line vty 0 7 
 
ATM(config)# line vty 0 7 
 

The supported commands can vary depending on the version of IOS software in use. To view a comprehensive list of commands, enter a question mark (?) at the prompt.

Switch(config-line)# ? 
 
ATM(config-line)# ? 
 

To exit line configuration mode and return to global configuration mode, use the exit command. To exit line configuration mode and return to privileged EXEC mode, enter the end command, or press Ctrl-Z.

Table 1-2: Command Summary

Commands		Description
User EXEC mode
	clear mac-address-table	Deletes all addresses in the MAC address table.
	show cluster	Shows a summary of the cluster to which the switch belongs.
	show cluster candidates	Shows switches that are not currently members of the cluster but could be.
	show cluster members	Shows all members in a cluster
	show cluster view	Shows a view of neighbors in a cluster.
	show ntp associations	Shows the status of NTP associations
	show ntp status	Shows the status of NTP.
	show spanning-tree	Displays Spanning-Tree Protocol (STP) information.
	show vlan	Displays information about a VLAN.
	show version	Show the firmware version for the switch or module.
	show vtp	Displays general information about the VTP management domain, status, and counters.
Privileged EXEC mode
	clear cgmp	Deletes the multicast addresses and router ports maintained by Cisco Group Management Protocol (CGMP).
	clear ip address	Deletes the IP address without disabling the IP processing.
	clear mac-address-table	Deletes all addresses in the MAC address table.
	clear vmps statistics	Clears the statistics maintained by the VLAN Query Protocol (VQP) client.
	clear vtp counters	Clears the VLAN Trunk Protocol (VTP) counters.
	cluster setup	Automatically builds a cluster.
	copy tftp	Downloads a new Flash image for the ATM module.
	delete	Deletes a file from the file system.
	rcommand	Executes commands on a cluster member from the command switch.
	session	Logs into an ATM module.
	show cgmp	Displays the current state of the CGMP-learned multicast groups and routers.
	show file system	Shows information about local and remote file systems.
	show interface	Displays the administrative and operational status of a switching (nonrouting) port.
	show mac-address-table	Displays the MAC address table.
	show port block	Displays the blocking of unicast and multicast filtering for the port.
	show port group	Displays the ports that are assigned to groups.
	show port monitor	Displays the ports that have port monitoring enabled.
	show port network	Displays the network ports on the switch.
	show port security	Displays the ports that have port security enabled.
	show port storm-control	Displays the setting of broadcast-storm control.
	show tacacs	Displays various T+ server statistics.
	show vmps	Displays the VQP version, reconfirmation interval, retry count, server IP addresses, and current and primary servers.
	show vmps statistics	Displays the VQP client-side statistics.
	vlan database	Enters VLAN database mode.
	vmps reconfirm	Sends VQP queries to reconfirm all dynamic VLAN assignments with the VLAN Membership Policy Server (VMPS).
Global configuration mode
	cgmp	Enables CGMP.
	cluster member	Adds members to the cluster.
	cluster enable	Turns on the cluster command feature for a device.
	cluster commander-address	Adds a switch to the cluster. Only the command switch uses this command.
	enable last-resort	Specifies what happens if the TACACS and Extended TACACS servers used by the enable command do not respond.
	enable use-tacacs	Enables the use of TACACS to determine whether a user can access the privileged command level.
	interface	Selects an interface to configure.
	mac-address-table aging-time	Sets the length of time that a dynamic entry remains in the address table.
	mac-address-table dynamic	Adds a dynamic address entry to the address table.
	mac-address-table secure	Adds a secure address entry to the address table.
	mac-address-table static	Adds a static address entry to the address table.
	ntp access-group	Controls access to the system's NTP services.
	ntp authenticate	Enables NTP authentication.
	ntp authentication-key	Defines an authentication key for NTP.
	ntp broadcastdelay	Sets the estimated round-trip delay between the Cisco IOS software and an NTP broadcast server.
	ntp clock-period	Determines the clock error.
	ntp max-associations	Sets the maximum number of NTP associations that are allowed on a server.
	ntp peer	Configures the router's system clock to synchronize a peer or to be synchronized by a peer.
	ntp server	Allows the router's system clock to be synchronized by a time server.
	ntp source	Uses a particular source address in NTP packets.
	ntp trusted-key	Authenticates the identity of a system to which NTP will synchronize.
	shutdown vlan	Shuts down local traffic on the specified VLAN.
	snmp-server enable traps vlan-membership	Enables SNMP notification for VMPS changes.
	snmp-server enable traps vtp	Enables SNMP notification for VTP changes.
	snmp-server host	Specifies the host that receives SNMP traps.
	spanning-tree	Enables an instance of STP.
	spanning-tree forward-time	Specifies the forward delay interval for the switch.
	spanning-tree hello-time	Specifies the interval between hello Bridge Protocol Data Units (BPDUs).
	spanning-tree max-age	Changes the interval the switch waits to receive BPDUs from the root switch.
	spanning-tree priority	Configures the bridge priority for the specified spanning-tree instance.
	spanning-tree protocol	Defines the type of STP.
	spanning-tree uplinkfast	Accelerates the choice of a new root port when a link or switch fails or when STP reconfigures itself.
	tacacs-server attempts	Controls the number of login attempts that can be made on a line set up for TACACS, Extended TACACS, or TACACS+ verification.
	tacacs-server directed-request	Sends only a username to a specified server when a direct request is issued in association with TACACS, Extended TACACS, and TACACS+.
	tacacs-server dns-alias-lookup	Enables IP Domain Name System alias lookup for TACACS+.
	tacacs-server extended	Enables an extended TACACS mode.
	tacacs-server host	Specifies a TACACS, Extended TACACS, or TACACS+ host.
	tacacs-server key	Sets the authentication encryption key used for all TACACS+ communications between the access server and the TACACS+ daemon.
	tacacs-server last-resort	Causes the network access server to request the privileged password as verification for TACACS or Extended TACACS or to allow successful login without further input from the user.
	tacacs-server login-timeout	Specifies the maximum amount of time in seconds to wait for a TACACs login.
	tacacs-server optional-passwords	Specifies that the first TACACS request to a TACACS or Extended TACACS server be made without password verification.
	tacacs-server retransmit	Specifies the number of times the Cisco IOS software searches the list of TACACS or Extended TACACS server hosts before giving up.
	tacacs-server timeout	Sets the interval that the server waits for a TACACS, Extended TACACS, or TACACS+ server to reply.
	vmps reconfirm	Changes the reconfirmation interval for the VQP client.
	vmps retry	Configures the per-server retry count for the VQP client.
	vmps server	Configures the primary VMPS and up to three secondary servers.
	vtp file	Modify the VTP configuration storage filename.
VLAN database mode
	abort	Abandons the proposed new VLAN database, and return to privileged EXEC mode.
	apply	Implements the proposed new VLAN database, propagate it throughout the administrative domain, and remain in VLAN database mode.
	exit	Implements the proposed new VLAN database, propagate it throughout the administrative domain, and return to privileged EXEC mode.
	reset	Abandons the proposed new VLAN database, and remain in VLAN database mode.
	show changes	Displays the differences between the currently implemented VLAN database on the switch and the proposed new VLAN database.
	show current	Displays the currently implemented VLAN database on the switch or a single selected VLAN from it.
	show proposed	Displays the proposed new VLAN database or a single selected VLAN from it.
	vlan	Configures a VLAN by its VLAN ID.
	vtp	Configures the VTP mode.
	vtp domain	Configures the VTP administrative domain.
	vtp password	Configures the VTP password.
	vtp pruning	Enables pruning in the VTP administrative domain.
	vtp v2-mode	Enables VTP version 2 mode in the administrative domain.
Interface configuration mode
	duplex	Specifies the duplex mode of operation for a port.
	flowcontrol	Controls traffic rates during congestion.
	ntp broadcast client	Allows the system to receive NTP broadcast packets on an interface.
	ntp broadcast destination	Configures an NTP server or peer to restrict broadcast of NTP frames to the IP address of a designated client or a peer.
	ntp broadcast key	Configures an NTP server or peer to broadcast NTP frames with the authentication key embedded into the NTP packet.
	ntp broadcast version	Specifies an interface to send NTP broadcast packets.
	ntp disable	Prevents an interface from receiving NTP packets.
	ip address	Sets a primary or secondary IP address of a port.
	port block	Prevents the flooding of unknown destination MAC addresses and multicast addresses on this port.
	port group	Places a port into a port aggregation group.
	port monitor	Implements port monitoring on this port.
	port network	Enables a port as the network port for a VLAN.
	port security	Enables port security on a port.
	port storm-control	Disables broadcast traffic if too many broadcast packets are seen on this port.
	shutdown	Disables a port.
	spanning-tree cost	Sets a different path cost.
	spanning-tree portfast	Enables the Port Fast option on the switch.
	spanning-tree port-priority	Configures the STP priority of a port.
	speed	Specifies the speed of a port.
	switchport access	Configures a port as an access or dynamic VLAN port.
	switchport mode	Configures the VLAN membership mode of a port.
	switchport multi	Configures a port to be a multi-VLAN port.
	switchport trunk allowed vlan	Controls which VLANs can receive and transmit traffic on the trunk.
	switchport trunk encapsulation	Sets the encapsulation format on the trunk.
	switchport trunk native	Sets the native VLAN for untagged traffic when in IEEE 802.1Q trunking mode.
Line configuration mode
	login authentication	Applies the authentication list to a line or set of lines.
	login local	Changes a login username.
	login tacacs	Configures your switch to use TACACS user authentication.